1. Field of the Invention
The present invention relates generally to electrical circuits, and more particularly but not exclusively to copper structures of integrated circuit chips.
2. Description of the Background Art
An integrated circuit (IC) chip includes input/output (I/O) pads that are electrically connected to electrical circuits of the IC chip. The I/O pads can be wire-bonded to pins of the IC chip packaging. An I/O pad can also be connected to a redistribution layer, which is an additional metal layer that makes the I/O pad available in another location of the IC chip. The redistribution layer is electrically connected to a solder bump, which allows the IC chip to be electrically connected to an external electrical circuit, such as another IC chip.